Two of the most debilitating aspects of Parkinson's Disease are akinesia, resulting from low levels of dopamine in the brain, and dyskinesia, a consequence of long term use of drugs used in the treatment of Parkinson's Disease. The effects of low levels of dopamine on a person's mobility range from the complete inability to initiate ambulation to small little "stutter" steps (festination) to normal walk which suddenly freezes. These problems correspond to the so-called "off" periods which many Parkinson Disease subjects experience several times during the day and which result when the level of dopamine in the brain falls below therapeutic levels. Dyskinesia is a consequence of long term use of dopamine resulting in uncontrollable excessive motor activity, a kind of super sensitivity to dopamine. Dyskinesia occurs during so-called on periods in the presence of therapeutic or elevated levels of dopamine in the brain. Most people who suffer from long term Parkinson's Disease cycle between "on" and "off" periods and the related gait and motor problems several times a day.
At the preset time, attempts to control these debilitating aspects of Parkinson's Disease have centered around pharmacological and surgical approaches. Pharmacological attempts involve adjusting dosages, combinations, absorption and routes of administration of various drugs. Success is generally modest at best and transient as the disease relentlessly progresses. Surgical attempts have been made, specifically modified Ventral Pallidotomy and dopaminergic cell implantation procedures. While both pharmacological and surgical approaches offer promise neither provide a reliable solution to the debilitating aspects of the disease.
Kinesia paradoxa is a phenomenon which has long been reported in the literature. In the presence of so-called "visual cues" certain Parkinsonian subjects can overcome akinesia and related gait problems even when unmedicated or undermedicated. There are a variety of visual cues which are effective in evoking this response in receptive individuals. Most of these visual cues involve objects that the individual perceives as stepping over. An example of such a visual cue would be an array of ordinary playing cards on the floor at one's feet, spaced at intervals equal to or slightly greater than the subject's walking stride length and placed so as to align to his/her vector of gait.
Therefore, one of the objectives of the present invention is to provide "virtual" cues which evoke the same response as the real visual cue.